Oxygen tank key



FIG. 1 is a front elevational view of an “oxygen tank key” showing mynew design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a left side elevational view thereof; and,

FIG. 7 is a perspective view thereof.

The broken lines in FIG. 3, which define the bounds of the claimeddesign, form no part thereof.

The ornamental design for an “oxygen tank key,” as shown and described.